U.S. patent application number 12/730581 was filed with the patent office on 2010-09-30 for truck mixer.
This patent application is currently assigned to LIEBHERR-MISCHTECHNIK GMBH. Invention is credited to Berthold Ruf, Martin Wittig.
Application Number | 20100246313 12/730581 |
Document ID | / |
Family ID | 42340923 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100246313 |
Kind Code |
A1 |
Ruf; Berthold ; et
al. |
September 30, 2010 |
Truck Mixer
Abstract
The present invention relates to a truck mixer with a mixing
drum mounted and rotatable on a vehicle chassis, wherein the mixing
drum is supported on the rear by means of a large roller
bearing.
Inventors: |
Ruf; Berthold; (Schoneburg,
DE) ; Wittig; Martin; (Biberach, DE) |
Correspondence
Address: |
DILWORTH & BARRESE, LLP
1000 WOODBURY ROAD, SUITE 405
WOODBURY
NY
11797
US
|
Assignee: |
LIEBHERR-MISCHTECHNIK GMBH
Bad Schussenried
DE
|
Family ID: |
42340923 |
Appl. No.: |
12/730581 |
Filed: |
March 24, 2010 |
Current U.S.
Class: |
366/63 |
Current CPC
Class: |
B28C 5/4265
20130101 |
Class at
Publication: |
366/63 |
International
Class: |
B28C 5/18 20060101
B28C005/18 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 25, 2009 |
DE |
UM202009004187.5 |
Claims
1. A truck mixer (1) with a mixing drum (2) mounted and rotatable
on a vehicle chassis (11), wherein the mixing drum (2) is mounted
on the rear by a large roller bearing (14).
2. The truck mixer (1) according to claim 1, wherein the large
roller bearing (14) fully encloses the mixing drum (2) and/or that
the large roller bearing (14) has an inner race, and the inner race
of the large roller bearing (14) is attached to the outside of the
mixing drum (2) on the rear, preferably on the rear edge of the
mixing drum (2).
3. The truck mixer (1) according to claim 1, wherein at least one
compensating means (15) is directly and/or indirectly connected
with the large roller bearing (14), by which relative movements are
made possible in axial direction of the truck mixer (1).
4. The truck mixer (1) according to claim 1, wherein the
compensating means (15) comprises a pivotal connection (16, 17)
and/or that the large roller bearing (14) is connected with the
chassis by a pivotal connection (16, 17).
5. The truck mixer (1) according to claim 3, wherein the
compensating means (15) comprises a prop (15) and at least one at
least partly pivotable bearing (16, 17) and/or that the pivotal
connection (16, 17) is releasably attached to the truck mixer
(1).
6. The truck mixer (1) according to claim 5, wherein the bearing
(16, 17) is a rotatable bolt connection (16, 17).
7. The truck mixer (1) according to claim 5, wherein the prop (15)
includes a bearing (16, 17) each on the chassis side and on the
bearing side, by which relative movements are made possible in
axial direction of the truck mixer (1).
8. The truck mixer (1) according to claim 7, wherein the
chassis-side bearing (17) is articulated to the end of the chassis
(11), preferably to the outermost end of the chassis (11).
9. The truck mixer (1) according to claim 7, wherein the
support-side bearing (16) is eccentrically articulated to the large
roller bearing (14).
10. The truck mixer (1) according to claim 5, wherein the prop (15)
is an angle bracket (15) and/or two props (15) are provided.
11. The truck mixer (1) according to claim 10, wherein the angle
bracket (15) has two legs (15', 15''), and the first leg (15') is
longer than the second leg (15'').
12. The truck mixer (1) according to claim 11, wherein the legs
(15', 15'') of the angle bracket (15) include an obtuse or reflex
angle, in particular an angle in the range between 100.degree. and
150.degree., in particular between 120.degree. and 150.degree.,
particularly preferably an angle of 135.degree..+-.5.degree..
13. The truck mixer (1) according to claim 1, wherein the
attachment of the large roller bearing (14) is effected by means of
releasable fastening means or by a welded joint.
14. The truck mixer (1) according to claim 1, wherein in the rear
region below the mixing drum (2) a water tank (6) is arranged.
15. The truck mixer (1) according to claim 1, wherein the mixing
drum (2) can be driven via the large roller bearing (14) and/or in
the vicinity of the large roller bearing (14) means are provided,
by which the mixing drum (2) can be driven.
16. The truck mixer (1) according to claim 2, wherein at least one
compensating means (15) is directly and/or indirectly connected
with the large roller bearing (14), by which relative movements are
made possible in axial direction of the truck mixer (1).
17. The truck mixer (1) according to claim 16, wherein the
compensating means (15) comprises a pivotal connection (16, 17)
and/or that the large roller bearing (14) is connected with the
chassis by a pivotal connection (16, 17).
18. The truck mixer (1) according to claim 3, wherein the
compensating means (15) comprises a pivotal connection (16, 17)
and/or that the large roller bearing (14) is connected with the
chassis by a pivotal connection (16, 17).
19. The truck mixer (1) according to claim 2, wherein the
compensating means (15) comprises a pivotal connection (16, 17)
and/or that the large roller bearing (14) is connected with the
chassis by a pivotal connection (16, 17).
20. The truck mixer (1) according to claim 17, wherein the
compensating means (15) comprises a prop (15) and at least one at
least partly pivotable bearing (16, 17) and/or that the pivotal
connection (16, 17) is releasably attached to the truck mixer (1).
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a truck mixer with a mixing
drum mounted and rotatable on a vehicle chassis, wherein a bearing
of the mixing drum consists of a bearing pair comprising a race and
at least one castor.
[0002] In known concrete mixing trucks, the part of the mixing drum
pointing towards the rear of the vehicle is supported on two
rollers so as to rest freely thereon. In this way, a compensation
for otherwise occurring tensions or deformations e.g. by torsions
of the chassis in driving operation can be created by possible
relative movements in axial direction.
[0003] The free support prevents the occurrence of tensions in the
drum bearing due to movements or deformations in the chassis, since
as a result of these deformations relative movements can occur
between race and roller.
[0004] Due to these relative movements in axial direction, the
roller must be significantly wider than the race, in order to
ensure the safe support in all driving conditions. In all
attachment parts in the rear region of the drum, clearances must
also be provided for these movements. However, the utilization of
the installation space available thereby is restricted. For
example, the accommodation of filling and/or draining parts is
limited.
[0005] Since the angular position between race and roller can
change as a result of said deformations, either the roller or the
race is constructed with a crowned surface, so as to always ensure
sufficient rest in rolling contact. Such pairing of roller
bearings, however, is not optimal, since rolling also is effected
in axial direction. Furthermore, such pairing of roller bearings
places high demands on material and construction.
[0006] Furthermore, with this type of bearing it can occur that the
mixing drum is lifted off from the rollers e.g. when driving
through potholes. When the drum returns to the rollers, this
"bouncing" results in increased mechanical loads and an increased
nuisance by noise.
[0007] Since the bearing furthermore is completely open and
accessible to the environment, dirt can attach to the race and lead
to an increased wear of race and rollers. The attachment of dirt
also can increase the noise emissions. Furthermore, the access to
the contact region of castors and race must be protected by special
covers, in order to prevent possible dangers caused by drawing-in
and/or squeezing by this bearing pair.
SUMMARY OF THE INVENTION
[0008] Therefore, it is the object of the present invention to
develop a truck mixer as mentioned above in an advantageous way, in
particular to the effect that the same includes a rear-side bearing
which operates with less wear and is safer in operation and in
which a smoother running of the mixing drum is possible.
[0009] In accordance with the invention, this object is solved by a
truck mixer with the features of claim 1 Accordingly, it is
provided that a truck mixer includes a mixing drum mounted and
rotatable on a vehicle chassis, wherein the mixing drum is
supported on the rear by means of a large roller bearing.
[0010] The use of a large roller bearing involves the advantage
that a smooth-running, wear-optimized and low-noise-emission pair
of roller bearings and in particular a standard part can be used.
Since such large roller bearings also are available in encapsulated
form, it is no longer necessary to ensure an inaccessibility of the
bearing components rolling on each other or to make them less
accessible by additional covers. Since the support by means of
large roller bearings is no free support, "bouncing" of the mixing
drum no longer can occur e.g. when driving through potholes.
[0011] Furthermore, it can be provided that the large roller
bearing fully encloses the mixing drum and/or that the large roller
bearing has an inner race, wherein the inner race of the large
roller bearing is attached to the outside of the mixing drum on the
rear, preferably on the rear edge of the mixing drum. Since the
positions of the bearing and of the drum outlet thus can no longer
move relative to each other, the clearances for filling and/or
draining parts can be reduced and hence their properties can be
improved.
[0012] Furthermore, it is possible that at least one compensating
means is directly and/or indirectly connected with the large roller
bearing, by means of which relative movements are made possible in
axial direction of the truck mixer. This involves the advantage
that no tensions can be introduced into the chassis and/or also
vice versa from the chassis into the large roller bearing.
[0013] In addition, it is conceivable that the compensating means
comprises a pivotal connection and/or that the large roller bearing
is connected with the chassis by means of a pivotal connection.
[0014] Advantageously, the compensating means comprises a prop and
at least one at least partly pivotable bearing and/or the pivotal
connection is releasably attached to the truck mixer. For example,
assembly directly to the stationary outer race of the large roller
bearing is possible, whereby weight can advantageously be saved for
supporting parts and adjusting activities during assembly. The
omission of these supporting parts likewise improves the
accessibility to the mixing drum in the outlet region and thus
facilitates cleaning. Furthermore, the maintenance and in
particular the replacement of defective parts is facilitated.
[0015] It can be provided that the bearing is a rotatable bolt
connection. This provides for a particularly simple and efficient
bearing, for example by a pairing of bolt and sliding bush, which
ensures e.g. the necessary movement in axial direction.
[0016] Furthermore, it is possible that the prop includes one
bearing each on the chassis side and on the bearing side, by means
of which relative movements are made possible in axial direction of
the truck mixer.
[0017] Advantageously, it can be provided that the chassis-side
bearing is articulated to the end of the chassis, preferably to the
outermost end of the chassis.
[0018] Furthermore, it is possible that the support-side bearing is
eccentrically articulated to the large roller bearing.
[0019] Advantageously, the prop is an angle bracket and/or two
props are provided. Relative movements in axial direction between
the rear-side bearing and the chassis hence are possible, so that a
load compensation can take place. Supporting the bearing by means
of e.g. movable props furthermore can provide the advantage that
one bearing point each per chassis frame side is sufficient. This
results in a considerable gain in installation space below the
mixing drum, which can be utilized for accommodating components of
the truck mixer system.
[0020] In addition, it can be provided that the angle bracket has
two legs, with the first leg being longer than the second leg.
[0021] Advantageously, the legs of the angle bracket include an
obtuse or reflex angle, in particular an angle in the range between
100.degree. and 150.degree., in particular between 120.degree. and
150.degree., particularly preferably an angle of
135.degree..+-.5.degree..
[0022] It is possible that the attachment of the large roller
bearing is effected by means of releasable fastening means. As a
result, a replacement in the case of a defect is easily possible.
The so far higher maintenance costs as a result of the welded
connections of the components of the rear bearing can now be
avoided.
[0023] In principle, however, it is also possible that the
attachment of the large roller bearing is at least partly effected
by means of welded joints.
[0024] Particularly advantageously, a water tank is arranged in the
rear region below the mixing drum. Due to the rear bearing in
accordance with the invention, a considerable gain in installation
space can be obtained for example in the rear region below the
mixing drum. This gain in installation space can be utilized e.g.
for the installation of the water tank of the water system,
possibly even of the entire water system of the truck mixer. As a
result, the center of gravity of the entire vehicle is lowered. At
the same time, installation space overlaps between water tank and
exhaust gas system of the carrier vehicle can be avoided.
[0025] Furthermore, it can be provided that the mixing drum can be
driven via the large roller bearing and/or that in the vicinity of
the large roller bearing means are provided by means of which the
mixing drum can be driven. As a result, the transmission in the
vicinity of the drum base or at the front end of the mixing drum
can be omitted and be replaced by a simple and much less expensive
bearing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Further details and advantages will now be explained in
detail with reference to an embodiment illustrated in the drawing.
In which:
[0027] FIG. 1: shows a schematic view of a known truck mixer;
[0028] FIG. 2: shows a sectional representation A-A of the rear
bearing of the mixing drum of the truck mixer shown in FIG. 1;
and
[0029] FIG. 3: shows a schematic view of a truck mixer in
accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] FIG. 1 shows a known truck mixer 1 in accordance with the
prior art, which includes a rotatable mixing drum 2 mounted on a
truck with a built-in spiral not shown in detail. By rotating the
drum 2 in one direction, charge can be drawn in and thoroughly
mixed, and by rotating in the opposite direction, the charge can be
conveyed out.
[0031] Beside the mixing drum 2, the main components of the truck
mixer body are the supporting structure 3 of the rear bearing 19 of
the mixing drum 2, the rotary drive 4 of the mixing drum 2, chutes
and funnels 5 for charging and discharging, and a water system 6
and a ladder 7 e.g. for cleaning the body. The supporting structure
3 is mounted on the rear of the chassis 11 of the truck mixer 1. A
comparable supporting structure 3 is also provided for attachment
of the front bearing of the mixing drum 2 on the chassis 11.
[0032] At its front end, the drum base 12, the mixing drum 2 is
attached to a rotatable flange of a transmission 8, in order to
transmit the power of the drive components, in particular of the
rotary drive 4, to the mixing drum 2. The flange of the
transmission 8 is mounted in pendulum fashion, in order to
compensate the movements of the mixing drum 2 by deformations in
the chassis 11 of the truck. Such deformations can occur in
particular in driving operation, for example during use of the
truck mixer 1 as concrete mixer on its way from the concrete
factory to the site of use. On this way, the material to be mixed,
here concrete, must be intermixed continuously, in order to prevent
a solidification and hardening of the material to be mixed.
[0033] To provide for relative movements in axial direction of the
vehicle in the backward, rear region of the mixing drum 2, the
mixing drum 2 freely rests on two castors 9. To prevent the mixing
drum 2 from being deformed under dead load due to the weight at the
support or the rear bearing, a race 10 is firmly welded to the
mixing drum 2. In this way, the mixing drum is reinforced in the
bearing region, so that a deformation under dead load cannot
occur.
[0034] FIG. 2 shows the section A-A as it is indicated in FIG. 1.
The race 10 stands on the castors 9, so that in the case of a
rotation of the mixing drum 2 race 10 and rollers 9 will roll on
each other.
[0035] FIG. 3 shows an embodiment of a truck mixer 1 of the
invention in a schematic view. Equal components as in FIGS. 1 and 2
are designated with the same reference numerals.
[0036] The so far free rear support 19 of the mixing drum 2 with a
race 10 on rollers 9 is replaced by a large roller bearing 14
screwed to the mixing drum 2, which is connected with the chassis
frame 11 via movably mounted props 15.
[0037] Due to the firm connection of the mixing drum 2 to the
chassis frame 11, "bouncing" in driving operation of the truck
mixer 1 no longer can occur. Due to the movably mounted props 15,
however, no tensions are introduced into the chassis frame 11
and/or vice versa into the large roller bearing 14.
[0038] The large roller bearing 14 is configured as an encapsulated
roller bearing 14. Due to the use of the large roller bearing 14,
the drum operation is much smoother and safer. The noise emissions
are lower than in known truck mixers and no additional protective
covers are required any longer, since due to its encapsulation the
large roller bearing 14 does not provide for an unimpeded access to
the components rolling on each other.
[0039] Since the rear bearing is supported on movably mounted props
15, one bearing point per chassis frame side is sufficient, whereby
a considerable gain in installation space is obtained below the
mixing drum 2. Due to the movably mounted props 15, no tensions are
introduced into the chassis frame and the necessary relative
movements are made possible in axial direction. The props 15 are
mounted in rotatable bolt connections 16, 17 both on the chassis
side and on the bearing side. Both the chassis-side bearing 17 and
the support-side bearing 16 are a pairing of bolt and sliding bush,
which provides for a relative movement in axial direction of the
truck mixer 1.
[0040] The two props 15 are configured as angle brackets 15, with
the chassis-side first leg 15' being longer than the bearing-side
second leg 15''. The legs 15', 15'' include an angle of about
135.degree..
[0041] Since the positions of the bearing and of the drum outlet no
longer can move relative to each other, the clearances for filling
and/or draining parts are reduced in the embodiment of the truck
mixer 1 of the invention as described here.
[0042] In a particularly advantageous embodiment, the gain in
installation space below the mixing drum 2 is utilized for the
installation of a water tank 6, whereby the center of gravity of
the entire vehicle 1 is lowered. Thus, installation space overlaps
between water tank 6 and exhaust gas system likewise are
avoided.
[0043] Since all parts of the rear bearing are screwed, a
replacement in the case of a defect is easily possible.
[0044] In a further, non-illustrated embodiment of the invention it
is possible to drive the mixing drum 2 via the large roller bearing
14. As a result, the transmission 8 can be omitted and can be
replaced by a likewise non-illustrated bearing of simpler
construction, lighter in weight and less expensive.
* * * * *